The robbery of the treasure in the tower proves to be an exciting challenge to Frank and Joe. Frank and Joe attempt to foil a ruthless espionage ring in their effort to sabotage the United States space program.

When the Hardy Boys set out to solve the mystery of their missing chums, they discover a gang hide-out in a cave on an island along the way.

Frank and Joe Hardy look for clues in this perplexing mystery.

While attending an amusement park under the new ownership of their friend Daisy, Joe and Frank investigate the disappearance of a patron who was last seen riding a hit attraction, an event that has threatened Daisy's family's livelihood.

Frank and his brother, Joe, are excited! ...their team, the Bayport Bandits, has a real shot at winning. ...The charm is their teammate Jason's mitt. His dad, a major-league pitcher, wore it in the World Series! ... Right before the game, Jason's mitt goes missing! The team is devastated. Can Frank and Joe solve the case of the missing mitt before the Bandits lose the game?

When they are invited to spend Christmas vacation at the private island retreat of wealthy Elroy Jefferson, the Hardy boys become involved in two mysteries: the disappearance of Mr. Jefferson's grandson and the theft of a priceless collection of antique medals.

Teenaged detectives Joe and Frank Hardy uncover a plot to sabotage a ski resort.

Frank and Joe unravel clue after clue in this adventure-packed search for the living descendant of the mighty Aztec nation which once ruled Mexico.

Hired to locate an old Spanish cannon, the Hardy brothers uncover an even greater treasure after perilous underwater adventures.

Frank and Joe, the Hardy boys, solve a mystery involving a magician, American secret agents, and international spy ring, and a Scottish castle.